Pseuderanthemum multiflorum (Acanthaceae), a new species known only from Thailand, is here described and illustrated. It is distinguished from P. graciliflorum by inner corolla tube and pistil being glabrous instead of puberulous and by calyx lobes 4.5–6 mm long instead of 3–4 mm long. Comparison of morphological characteristics are provided.
Two new species, Rhododendron trichopetalum and R. yalaense, from Peninsular Thailand, are described and illustrated. Three new records of R. jasminiflorum, R. klossii and R. robinsonii are newly reported for Thailand, and R. klossii is herein reinstated. Lectotypifications were designated where required and an updated key to species, modified from the Flora of Thailand, is provided.
Lithocarpus is a major Asian endemic genus of (sub)tropical trees found throughout the region. The nearly 350 species can be difficult to identify in the absence of good fruiting material, often leading to confusion and misidentification. Once recognized as a distinct species, Lithocarpus longispinus is currently a heterotypic synonym of Lithocarpus wrayi. Following careful examinations and comparisons of herbarium specimens throughout the distribution range, along with in situ collections, we find distinct morphological differences between the two species. Here we define the diagnostic morphological traits, provide a complete description of the species along with an initial conservation assessment and propose the reinstatement of L. longispinus.
The new species Henckelia moniliformis (Gesneriaceae) is described from North-Eastern Thailand. A key to the species of Henckelia in Thailand is provided, along with illustrations, notes on the ecology and the IUCN conservation status of the new species.
Two new species, Greenea laotica (Rubiaceae) and Palaquium laoticum (Sapotaceae), are described based on specimens collected from the Nam Kading National Protected Area and its vicinity in central Laos. In addition, six taxa of angiosperms are reported as new records for the flora of Laos: Lonicera macrantha (Caprifoliaceae), Heritiera angustata, Heritiera parvifolia (Malvaceae), Olax imbricata (Olacaceae), Pellacalyx yunnanensis (Rhizophoraceae), Psychotria bonii (Rubiaceae), and Pouzolzia zeylanica var. calcicola (Urticaceae). For each species, voucher specimens are cited, photographs are shown and additional information including geographical distribution, ecology and taxonomic notes are provided. Lectotype is proposed for Olax imbricata.
Peliosanthes siamensis (Asparagaceae) is described from northern Thailand. A description, distribution, ecology, phenology, notes and illustration are provided. A provisional conservation status of the species in Thailand is also given.
A taxonomic revision of Mayodendron Kurz (Bignoniaceae) in Thailand is presented. One species, Mayodendron igneum (Kurz) Kurz, is enumerated with updated morphological description, morphological differences with the related species and illustrations, together with notes on distributions, a distribution map, habitats and ecology, phenology, conservation assessments, etymology, vernacular names, uses and specimens examined. The specimen Brandis 1357 at HBG [HBG522936] is lectotypified here for M. igneum . This species has a conservation status of Least Concern (LC). The leaflet laminas and wood anatomy and pollen morphology of this species are also reported in this study. M. igneum has bifacial leaflets, cyclocytic stomata, prismatic crystals in parenchyma around the vascular tissue and epidermal cells on both leaflet surfaces and its wood has diffuse-porous, biseriate, sometimes uniseriate, triseriate, tetraseriate heterocellular rays or uniseriate homocellular rays, with the procumbent cells up to 30 cells long. M. igneum has prolate-spheroidal or subprolate pollen shapes, small to medium sized, 19–25 µm in polar axis, 18–23 µm in equatorial axis, heterobrocate exine sculpturing. The pollen aperture patterns are classified as 4 types: typical tricolpate, 3-syncolpate with oblique colpi, 4-syncolpate and 6-pantocolpate.
Paraboea verticillata, previously only known from Peninsular Malaysia, has been found on a limestone outcrop in Yala Province, Southern Thailand. The species is described and illustrated here.
Psydrax comprises ten species in Thailand. Here, four new species, Psydrax celatus, P. maxwellii, P. minoriflorus, and P. pilosus are described from Thailand, and one lectotype is designated. Psydrax abbreviatus is a new combination.
A species of Thai Ilex (Aquifoliaceae), I. inthanonensis, is reported new to science. Ilex inthanonensis is glabrous on most parts except puberulent in the infructescences, leaf blade punctate below, fruiting pedicels shorter than or equalling fruit diameter, calyx 4–5-lobed, pyrenes 4–5 with 3–5(–6)-striae slightly elevated dorsally, not sulcate and laterally smooth. A morphological description is provided, just like photos and a line drawing. The new species is critically compared the most resembling species.
A species of Meliaceae, Aglaia bracteolata is newly added to the flora of Thailand. It was first recognized in Suan Hin Pha Ngam Forest Park, Loei Province, and is described and illustrated here. This species is found on the limestone hill, characterized by the presence of Cycas petraea and Dracaena cambodiana. It is also found in Phayao, Lampang and Kanchanaburi Provinces.
Three species of Curcuma subgen. Ecomatae, Curcuma bicolor, C. nakhonphanomensis, and C. rubroaurantiaca, are newly recorded for the flora of Laos. Descriptions and colour plates, as well as notes on ecology and phenology, are provided for all three species. In addition, a key to species of Curcuma subgen. Ecomatae in Laos is also provided.
Eleven species of Strobilanthes (Acanthaceae) are recorded from the Bolaven Plateau in southern Laos. A key to the species, photographs, vernacular names, taxonomic notes and information on distributions, habitat and phenology, are provided. In addition, two species (S. dalzielii and S. glaucescens) are lectotypified.
Mappianthus kachinensis, a new species currently only known from Kachin State, Putao District, northern Myanmar, is described and illustrated. A detailed description along with etymology, conservation status, and a line illustration are provided for a new species. The genus is still poorly known, and this discovery increases the number of species in Mappianthus to at least three. Problems with species delimitation in the genus are also briefly discussed.
A taxonomic account of the genus Pitardella in Thailand, with P. poilanei the sole species, is presented. Description, photographs and taxonomic notes are provided based on newly collected materials; in addition, a lectotype for P. poilanei is designated.
Phanera godefroyi, previously only known from Cambodia, is recorded for Thailand. A full description of Phanera godefroyi is provided for the first time, based on fresh specimens with flowers and fruits, accompanied by colour photographs to assist identification, added are notes on its ecology, phenology, and taxonomy. Evidence from nuclear (ITS) and chloroplast data (trnK/matK, the trnL intron and trnL–F spacer) in our phylogenetic study suggests that the species is sister to P. curtisii and P. scandens. In addition, pollen morphology examined with Light and Scanning Electron Microscopes supports the recognition of the species by its typical combination of palynological characters, like the prolate spheroidal shape, colpi with granules, a distinctly thickened annulus around the endoaperture areas, and a rugulate ornamentation of the exine.
Five Begonia species are recorded from Cambodia of which Begonia longifolia is reported for Cambodia for the first time. An updated checklist of Begonia with sectional classification, and species expected to occur in Cambodia are also provided, supplemented with photographs, information on geographical range and a distribution map showing occurrences in Cambodia.
The new species Chayamaritia sirindhorniana (Gesneriaceae) is described from materials collected in Loei Province in Northeastern Thailand. As it is currently only known from the type locality, further exploration of the region is needed to assess its conservation status.
Two species of the genus Thismia (Thismiaceae), T. angustimitra and T. javanica, from Nam Kading National Protected Area, central Laos, are recorded for Lao flora for the first time. The number of species of Thismia in Laos is raised to three, and a key to species of Thismia in Laos is provided.
Garcinia minutiflora (Clusiaceae), previously known only from Peninsular Malaysia, is reported as a new record from dry evergreen forest on limestone hills in Phangnga and Krabi Provinces, Peninsular Thailand. A detailed morphological description, illustrations and a distribution map of the species are presented, along with information on distribution, specimens examined, habitat, conservation assessment, phenology and vernacular name. In addition, G. minutiflora is lectotypified.
